Secretary of State Mike Pompeo said the United States was taking the measure due to China's push forward with a security law that Hong Kong activists say will curb the city's freedoms.

"We can no longer distinguish between the export of controlled items to Hong Kong or to mainland China," Pompeo said in a statement.

"We cannot risk these items falling into the hands of the People's Liberation Army, whose primary purpose is to uphold the dictatorship of the CCP by any means necessary," he said, referring to the Chinese Communist Party.

The State Department will end all exports to Hong Kong on its controlled list -- items ranging from advanced ammunition to military hardware that already need the green light from the administration and Congress.

The Commerce Department in turn will stop making a distinction between Hong Kong and China on so-called dual-use US products, which have both military and civilian applications -- and are highly restricted when sought by Beijing.

Pompeo announced the decision hours after China in turn restricted visas to some Americans for Hong Kong.

The United States has been leading global outrage over a proposed security law, which would outlaw subversion and other perceived offenses in Hong Kong, to which Beijing promised autonomy before it was handed back the territory from Britain in 1997.

"It gives us no pleasure to take this action, which is a direct consequence of Beijing's decision to violate its own commitments under the UN-registered Sino-British Joint Declaration," Pompeo said.